Binders

Information

  • Patent Grant
  • 8114210
  • Patent Number
    8,114,210
  • Date Filed
    Friday, August 1, 2008
    16 years ago
  • Date Issued
    Tuesday, February 14, 2012
    13 years ago
Abstract
An un-reacted substantially formaldehyde free curable binder solution for binding loose matter consists essentially of a solution obtainable by dissolving a reducing sugar, an ammonium salt acid precursor optionally a carboxylic acid or a precursor thereof and optionally ammonia in water.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national counterpart application of International Application Serial No. PCT/EP2008/060185, filed Aug. 1, 2008, under 35 USC §371, which claims priority to European Patent Application Serial Number 0715100.4, filed on Aug. 3, 2007, European Patent Application Serial Number 0807777.8, filed Apr. 29, 2008, and European Patent Application Serial Number 0810297.2, filed Jun. 6, 2008 the entire disclosures of each are hereby incorporated herein by reference.


TECHNICAL

This invention relates to binders, for example for glass wool or stone wool insulation.


BACKGROUND

WO 2007/014236 (incorporated herein by reference) relates to binders, including binders comprising Maillard reactants. One particular binder disclosed is based on a triammonium citrate-dextrose system derived from mixing dextrose monohydrate, anhydrous citric acid, water and aqueous ammonia. One of the many advantages of this binder system is that it is formaldehyde free.


SUMMARY

One aspect of the present invention provides a binder solution in accordance with claim 1; the dependent claims define alternative and/or preferred embodiments.


In another aspect, the present invention provides a binder solution comprising a solution obtainable by dissolving

    • a carbohydrate,
    • an acid precursor derivable form an inorganic salt,
    • a source of nitrogen
    • optionally an organic acid or a precursor thereof and
    • optionally ammonia.


Binder solutions used in accordance with the present invention may be “substantially formaldehyde free”, that is to say that they liberate less than 5 ppm formaldehyde as a result of drying and/or curing (or appropriate tests simulating drying and/or curing). Such binder solutions are preferably “formaldehyde free”, that is the say they liberate less than 1 ppm formaldehyde in such conditions.


Products in accordance with the invention which incorporate binders (for example insulation materials or wood boards) may be “substantially formaldehyde free”, that is to say that they comprise less than 5 ppm or less than detectable limits of free formaldehyde and/or consist of materials which together comprise less than these amounts of free formaldehyde and/or release levels of formaldehyde in standardised tests adapted to simulate their ordinary use which allows them to be classified as having no or undetectable levels of formaldehyde release. Preferably, such products release less than 10 μg/m3, more preferably less than 5 μg/m3 of formaldehyde during the period of 24-48 hours from the start of testing in accordance with ISO 16000.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 shows a plan view of a mineral fibre test sample, where r is radius=12.7 mm, DC is distance between centers=44.5 mm, a=25.4 mm, and b=121 mm.





DETAILED DESCRIPTION

It has been found that binders according to the present invention may have at least equivalent and indeed improved properties compared to, for example, the tri-ammonium citrate-dextrose system of WO 2007/014236. WO 2007/014236 teaches binder systems based, inter alia, on a combination of a carbohydrate (for example a reducing sugar), ammonia and a carboxylic acid and suggests that a Maillard type reaction may form the basis of the curing chemistry. It would have been thought that the nature of the acid used would have a significant effect upon the properties of the cured binder, particularly if the acid precursor and/or a derivative therefrom is incorporated into the structure of the cured binder. It is thus surprising that an acid precursor derivable from an inorganic salt should provide a suitable acid precursor in an otherwise apparently similar binder system.


Use of an acid precursor derivable from an inorganic salt may have significant advantages in terms of cost, availability and ease of handling. The acid precursor derivable from an inorganic salt of the binder solution may comprise a species selected from the group consisting of sulphates, phosphates, nitrates and carbonates. A particular advantage can be achieved by use of one or more inorganic ammonium salts, for example, an ammonium sulphate, an ammonium phosphate or an ammonium carbonate. An ammonium salt may provide the or part of the acid precursor and/or the or part of the source of nitrogen and/or the or part of a pH control system. An ammonium nitrate may also work; however, ammonium nitrate may oxidise aldehyde groups of the carbohydrate (for example in the case of dextrose) and/or require precautions to avoid explosions.


An ammonium sulphate is particularly advantageous but ammonium phosphate may be used in addition to or instead of this. Ammonium phosphate may be mono ammonium phosphate, di ammonium phosphate or tri ammonium phosphate; it may be an ammonium hydrogen phosphate. An ammonium carbonate, alone or in combination with the other materials disclosed herein, may also provide good results. The ammonium carbonate may be an ammonium bicarbonate.


The acid precursor, particularly when this consists essentially of inorganic ammonium salt(s), may make up

    • at least 5%, preferably at least 7%, more preferably at least 9% by dry weight of the uncured binder solution; and/or
    • less than 25% or 20%, preferably less than 18%, more preferably less than 16% by dry weight of the uncured binder solution.


The term “consist or consisting essentially of” is intended to limit the scope of a claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic(s) of the claimed invention.


The acid may comprise: a sulphuric acid, a phosphoric acid, a nitric acid or a weak acid.


The binder may comprise between 5% and 25%, preferably 10% to 20%, more preferably 15% to 20% by dry weight of acid precursor (particularly where this is an inorganic ammonium salt) to carbohydrate (particularly when this is a sugar).


Where the binder comprises both an acid precursor derivable from an inorganic salt and an organic acid, these may be present in the following amounts by dry weight with respect to the carbohydrate (particularly where this is a sugar):

















Preferred
More preferred
Most preferred



















acid precursor
At least 2.5%
At least 5%



derivable from an


inorganic salt


organic acid
At least 2.5%
At least 5%


Combination of
5-25%
10-20%
15-20%


organic acid and


acid precursor


derivable from an


inorganic salt









Where an organic acid is used, this is preferably derived from an ammonium salt. For example, an ammonium citrate, particularly tri-ammonium citrate may be used as a source of citric acid.


Prior art phenol formaldehyde binder systems for mineral wool insulation have been used with the addition of about 2% by weight ammonium sulphate as a curing agent. However, the chemistry of such phenol formaldehyde binder systems is not comparable to the binder systems of the present invention which are not based on phenol and/or formaldehyde and/or on other phenolics.


A carbohydrate may be used in the binder solution rather than specifically a reducing sugar and may comprise a monosaccharide, for example in its aldose or ketose form. Preferably, the carbohydrate comprises a sugar, more preferably a reducing sugar or a reactant that yields a reducing sugar in situ under thermal curing condition; it may comprise glucose (ie dextrose). The carbohydrate may comprise a carbohydrate having a reducing aldehyde. It is believed that the use of a reducing sugar and particularly dextrose gives good binder strengths, particularly for the manufacture of mineral wool insulation products. The dextrose need not be 100% pure but use of a material having a dextrose equivalent value of at least 0.85, preferably at least 0.9 and more preferably at least 0.95 is thought to be advantageous. The dextrose equivalent value DE can be thought of as i) a measure of de-polymerization and is roughly: DE=100/dp where dp stands for degree of polymerization or ii) the total amount of reducing sugars calculated as D-glucose (dextrose) on a dry basis.


Preferably, the binder solution and/or the binder is free or substantially free of starch; the presence of substantial quantities of starch is thought to increase the curing time and/or reduce the strength of the cured binder. The binder solution and/or the binder may be free or substantially free of proteins.


Industrial, non-food grade dextrose may be used as the reducing sugar; products such as Sirodex331 which is a 75% solids sugar solution obtainable from Tate and Lyle with a DE value of 94.5 may be used.


The reducing sugar may consist essentially of dextrose. Particularly in this case and more particularly where, in addition, the acid precursor consists essentially of an ammonium salt, for example an ammonium sulphate, the ratio by dry weight of the amount of reducing sugar/the amount of acid precursor may be greater than or equal to 2.5 and/or less than or equal to 13.


The source of nitrogen may be an amine or an amine reactant; it may be derivable from the same source as the acid precursor, for example, from an inorganic ammonium salt. It is preferably ammonia in solution.


Precursors for and/or reactants which give the materials referred to may be used.


In one embodiment, the binder is derived essentially from a reducing sugar and an inorganic ammonium salt in aqueous solution.


In another embodiment, the binder may also comprise an organic acid, particularly a carboxylic acid; this may be a polycarboxylic acid, particularly a bi-carboxylic acid or tri-carboxylic acid, preferably citric acid; it is preferably monomeric. The combination of an organic acid (or a precursor a salt or an anhydride thereof) with an acid precursor derivable from an inorganic salt may present various advantages. Firstly, such a combination may reduce the risk of punking (which has been observed with such binders based solely on organic acids) whilst providing acceptable strength. Punking is a term of art in the mineral fibre insulation area which generally denotes a comparatively rapid oxidation of a binder with a concomitant generation of heat in a finished and generally packaged insulation product. Punking generally causes generation of fumes and discolouring of the insulation material. It may be associated with exothermic reactions which increase the temperatures through the thickness of the insulation material; this may destroy the integrity of the insulation product and/or present a fire hazard.


Alternatively or additionally, the combination of an organic acid (or a precursor, a salt or an anhydride thereof) with an acid precursor derivable from an inorganic salt may moderate acid conditions occurring during curing and thus reduce the risk or tendency of such conditions to cause significant damage to the material being bound. Such a combination may be particularly advantageous as a binder for stone wool insulation whose fibres may be more susceptible to potential damage by acid than, for example, glass wool insulation.


In a further embodiment, the binder is derived essentially from: a carbohydrate; an inorganic ammonium salt; and an organic acid and/or organic acid precursor; in aqueous solution.


Binders which comprise or consist essentially of the components described herein may include additives, for example, additives selected from: silanes, mineral oils, coupling agents, silicones or siloxanes (particularly for water repellency), silicon containing compounds, surfactants, hydrophilic additives, hydrophobic additives, waxes, substances useful for controlling the pH (e.g. ammonium hydroxide) and ammonia. Ammonium hydroxide when used, and indeed other additives, may provide the and/or an additional source of nitrogen.


Preferably, the total quantity of additives (excluding ammonia) is less than 5% by weight (excluding the weight of water present), more preferably less than 3% or less than 2% by weight.


Particularly for mineral fibre products, it is preferred to include a silane as an additive. The binder and/or binder solution may comprise at least 0.1% and/or less than 1% of a silane by dry weight. The silane may be amino substituted; it may be a silyl ether and it is believed that its presence may significantly improve the long term strength of the binder, particularly after weathering.


Preferences for the pH of the binder are:

















Preferred
More preferred
Most preferred





















pH of binder
≧7
≧8
≧9











at least in the state in which the binder is applied to a material to be bound and/or recovered in a waste water recuperation system. Such a neutral or alkaline pH of the binder may alleviate problems of corrosion of manufacturing equipment which have been encountered with some essentially acidic prior art binder systems. Such prior art binders include binders consisting essentially of polyacrylic acids or polymer polycarboxylic acids. One particular advantage of the present invention is thus the use of a binder system that can operate in such neutral or alkaline conditions. When cured, the binder may become acidic during the curing process. However, equipment corrosion considerations are less significant in this case due to the minimal contact between the manufacturing equipment and the binder when in this state. The pH of the binder may be less than or equal to 13, preferably less than or equal to 12, 11 or 10. A preferred pH may be in the range of 7.5 to 9.5, particularly 8 to 9. Binder which has been applied to the material to be bound and is subsequently dissolved in water may have a pH of greater than 6.


It is preferred to arrange the pH of the binder solution at an appropriate level to prevent precipitation of its constituents and particularly to ensure that the acid precursor derivable from an inorganic salt remains in solution. This is particularly the case where ammonium phosphate provides the acid precursor. Better dry and/or weathered strengths and/or more homogeneous products may be achieved by using homogeneous binder solutions comprising ammonium salt acid precursors which are free from precipitates, particularly when ammonium phosphate is used and the binder solution is free from phosphate precipitates.


The binder composition may be provided in the form of an aqueous solution; it may contain free ammonia or excess ammonia in solution. A neutral or alkaline pH of the binder may be generated by an excess of alkaline groups compared with acid groups present in the binder solution, for example, due partially or substantially to the presence of ammonia in the solution. Additional ammonia may be added to the binder solution, for example 0.2%-1% by weight, or indeed more; this may help to keep a wash water system alkaline over the long term, particularly for the manufacture of mineral wool insulation.


In the case or mineral wool fibres particularly for thermal insulation products, when binder solution is sprayed on to hot mineral wool fibres just after they have been formed, the residual heat of the mineral wool fibres may cause a significant portion of any water in the binder solution to evaporate. Consequently, the mineral wool fibres which are then collected to form a bat may have binder present on them in the form of a sticky, viscous or tacky liquid. This may facilitate bonding between individual fibres via the binder.


One of the many advantages of this binder system is that it is applied, for example sprayed onto mineral wool fibers, in a substantially unreacted state. The ability to apply the binder solution in a substantially unreacted state may alleviate problems associated with pre-reacting the binder components in solution which have been encountered with some prior art binder systems in which the components are pre-reacted. Such prior art binders include binders consisting essentially of pre-reacted polymers or resins which are applied to the materials to be bound. With substantially unreacted binder present in the form of a sticky, viscous or tacky liquid on the material to be bound, the reaction between the binder components may occur in a substantially dry state. One may describe the reaction as a bulk polymerization because it is occurring without the benefit of a solvent. A particular advantage of the present invention is thus the use of a binder system that can polymerise in a substantially dry state or through a bulk polymerisation.


Mineral fibres used in the context of the invention may be formed by internal or external spinning. They may have a temperature in the range 20° C. to 200° C., generally 30° C. to 100° C. or 150° C., when sprayed with the binder solution. The quantity of binder solution sprayed may be used with or without additional water sprays to assist in cooling the mineral fibres to a desired temperature between their formation and their collection to form a batt.


A particular advantage of using ammonia in solution to control the pH of the binder solution applied to the mineral fibres is that at least part of the ammonia of binder solution that sticks to the fibres may flash off due to the residual heat of the mineral wool fibres. Consequently, the binder solution that coats the fibres may have a lower pH than the binder solution sprayed.


The invention extends to a method of manufacturing a mineral fibre thermal insulation product comprising the sequential steps of:

    • Forming mineral fibres from a molten mineral mixture;
    • spraying a substantially formaldehyde free binder solution on to the mineral fibres, the binder solution comprising: a carbohydrate (particularly a reducing sugar), an acid precursor derivable from an inorganic salt and a source of nitrogen;
    • Collecting the mineral fibres to which the binder solution has been applied to form a batt of mineral fibres; and
    • Curing the bat comprising the mineral fibres and the binder by passing the batt through a curing oven so as to provide a bat of mineral fibres held together by a substantially water insoluble cured binder.


Wash water may be sprayed on to mineral fibres between their formation and their collection to form a bat, at least a part of the wash water having been sprayed on mineral fibres and subsequently returned to a wash water system to be reused as wash water. The binder solution may comprise wash water.


The binder may be curable; it may be cured, for example in a curing oven; it may form a thermoset binder. In its cured form, the binder may: comprise melanoidins; and/or be thermoset; and/or be water insoluble or substantially water insoluble. The binder solution may be substantially colourless or white to off-white; upon curing, the binder may take on a dark colour, particularly a dark brown colour. The cured product may be dark in colour, particularly dark brown in colour. The binder may be free of proteins; it may be free of cellulosic feedstock. One of the many advantages of this binder system is that the extent of curing can be determined by the colour. Substantially dehydrated binder appears white or off-white. Progressively cured to a greater extent, the binder appears progressively darker in colour (a darker shade of brown). When applied to mineral fibers, the extent to which the mineral wool insulation has cured can be determined by its colour.


When applied to the material to be bound and/or prior to curing, the binder may be free or substantially free of melanoidins and/or other reaction products derived from curing. Curing of the binder may produce glucosylamine, particularly as an intermediate product. Consequently, a cured or particularly a partially cured product may comprise glucosylamine.


The reaction of the binder upon curing may be essentially a Maillard type reaction as described for example in US Patent Application 20070027283 or WO2007/14236. The binder may comprise polymerisation products of a mixture that comprises a reducing sugar and a material selected from the group consisting of ammonium sulphate, ammonium phosphate, ammonium nitrate and ammonium carbonate.


The binder solution may be formulated by combining:

    • A carbohydrate, preferably a reducing sugar;
    • An acid precursor derivable from an inorganic salt, preferably an ammonium sulphate or ammonium phosphate;
    • A source of nitrogen; and
    • water.


The formulation may comprise optional or additional ammonia provided in the form of an aqueous ammonia solution. The water may comprise wash water or recycled process water.


Forming the binder solution from a carbohydrate and an acid precursor comprising an inorganic ammonium salt provides one particular advantageous preparation method. This may be achieved in a simple mixing chamber which may be open and/or at atmospheric pressure. The carbohydrate and/or the acid precursor may be added in powder or liquid form. The preparation is preferably carried out at room temperature. Preferably it is not necessary to supply heat to prepare the binder solution; nevertheless, the binder solution may be heated during its preparation, for example to a temperature with the range 20° C. to 80° C., particularly where this facilitates dissolving and/or mixing of its ingredients.


The binder solution, particularly in the state applied to the material to be bound, may comprise:

    • at least 5% 10%, 15% or 18% solids and/or
    • less than 70% or 60% (particularly in the case of wood board applications) or less than 50%, 40% or 20% solids (particularly in the case of mineral fibre insulation applications)


      particularly determined as bake out solids by weight after drying at 140° C. for 2 hours.


The collection of loose matter bound together by means of the binder solution may comprise materials selected from: fibres, fibrous materials, mineral fibres, glass fibres, stone wool fibres, cellulosic fibres (including wood fibres, wood shavings, wood particles and sawdust), wood veneers, facings, wood facings, particles, woven or non-woven materials, loosely assembled materials, woven or non-woven materials.


The binder solution and/or the binder are preferably organic.


The loose matter may be shaped and/or dimensioned and/or moulded with the aid of the binder. The material produced may be selected from: a thermal insulation material, a mineral fibre product, a wood board product (including chip board, orientated strand board, particle board, medium density fibre board, wood facing products), foundry sands.


The matter to be bound may be at a temperature in the range 20° C. to 100° C. when the binder is applied. Particularly in the case of wood boards products, the binder and the loose matter may be mechanically mixed, for example by tumbling. The binder solution, particularly when applied to the loose matter, may have a viscosity appropriate for application by spraying or pouring. Its viscosity at 20° C. may be:

    • Less than about 1.5 Pa·s, preferably less than about 1×10−2 Pa·s; and/or
    • Greater that about 2×10−4 Pa·s, preferably greater than about 5×10−4 Pa·s


Curing of the binder may occur in a curing oven, for example using forced hot air circulation; it may occur in a press. Curing may comprise a dehydration of the binder; it may comprise a polymerisation; it may comprise a bulk polymerisation reaction. Curing may be carried out for duration of 20 minutes or less, preferably 10 minutes or less; it may be carried out by passing the product (for example a mineral fibre batt) through at least one zone of a curing oven at a temperature within the range 230° C.-300° C. with an oven residence time in the range 30 seconds to 20 minutes. Curing of the binder preferably occurs when the binder solution (from which water may have been evaporated) is in contact with the loose matter; it may occur at substantially atmospheric pressure. The curing may be a substantially dry curing, that is to say by application of dry heat and/or substantially dry or heated atmospheric air rather than using steam or heated water vapour.


Particularly in the case of mineral fibre insulation products, the curing temperature and time may be selected as a function of the product density and/or thickness. The curing oven in such cases may have a plurality of heating zones having temperatures within the range 200° C. to 350° C. (typically 230° C. to 300° C.). A thin, low density product (12 kg/m3 or less) may be cured by passing through the curing oven in as little as 20 seconds; a thick, high density product (80 kg/m3 or more) may require a passage of 15 minutes or more in the curing oven. The product may reach a temperature in the range 180° C.-220° C. during the curing process.


The cured binder may comprise greater than 2% and/or less than 8% nitrogen by mass as determined by elemental analysis.


The binder in its uncured state may comprise the following levels of sulphates, phosphates carbonates and/or nitrates by dry weight:

    • Greater than 2.5%, 3% or 5%; and/or
    • Less than 25%, 22%, or 20%


Finished materials manufactured using binder systems according to the present invention may have residual levels of sulphates, phosphates, carbonates and/or nitrates derived notably from the inorganic salt serving as the acid precursor. Such species may be present in the following quantities:

    • Greater than 500, 750, 1000 or 1500 mg/kg; and/or
    • Less than 5000, 4000 or 3000 mg/kg.


The presence of such species may be assessed in a leach test and provide an indication in the final product of the binder system used.


The quantity of binder in the finished product, particularly in the case of mineral wool insulation, may be:

    • Greater than: 1%, 2%, 2.5%, 3%, 3.5% or 4%; and/or
    • Less than: 20%, 15%, 10% or 8%


      measured by dry weight of the finished product.


Particularly in the case of mineral fibre insulation, the products may have one or more of the following parting strengths:


Ordinary Parting Strength of






    • At least 120 g/g, preferably at least 150 g/g; and/or

    • Less than 400 g/g


      Weathered Parting Strength of

    • At least 120 g/g, preferably at least 150 g/g; and/or

    • Less than 400 g/g


      % loss between Ordinary and Weathered Parting Strength of

    • Less than 10%, preferably less than 5%





Where the product is mineral wool insulation may have one or more of the following characteristics:

    • A density greater than 5, 8 or 10 kg/m3;
    • A density less than 200, 180 or 150 km/m3
    • Comprise glass wool fibres and have a density greater than 5, 8 or 10 kg/m3 and/or less than 80, 60 or 50 kg/m3;
    • Comprise stone wool fibres and have a density greater than 15, 20 or 25 kg/m3 and/or less than 220, 200 or 180 kg/m3;
    • A thermal conductivity λ of less than 0.05 W/mK and/or greater than 0.02 W/mK
    • Comprise less than 99% by weight and/or more than 80% by weight mineral fibres.
    • A thickness of greater than 10 mm, 15 mm or 20 mm and/or less than 400 mm, 350 mm or 300 mm.


Where the product is wood board product, it may have one or more of the following characteristics:

    • Dimensions of at least 50 cm×80 cm, preferably at least 1 m×2 m
    • Thickness of at least 11 mm, 12 mm or 15 mm
    • A curing time of less than 25, 15, 12 or 10 minutes
    • An internal bond strength measured in accordance with EN319 of at least: 0.4 N/mm2 or 0.45 N/mm2 (particularly for particle board or fibre boards) or measured in accordance with EN300 of at least 0.28 N/mm2 (particularly for orientated strand board)
    • A thickness swelling after 24 hours in water at 20° C. according to EN317 of less than 12%, preferably less than 10%
    • A water absorption after 24 hours in water at 20° C. of less than 40%, preferably less than 30%
    • A modulus of elasticity according to EN310 of at least: 1800 N/mm2 (particularly for particle board or fibre boards) or 2500 N/mm2 (particularly for orientated strand board) or 3500 N/mm2 or 4800 N/mm2
    • A bending strength (MOR) of at least: 14 N/m2 (particularly for particle board or fibre boards) or 18 N/mm2 (particularly for orientated strand board) or 20 N/mm2 or 28 N/mm2
    • Wax as an additive, for example in the range 0.1 to 2% by weight, preferably 0.5 to 1% by weight
    • A resin content (weight of dry resin to weight of dry wood particles) in the range 8 to 18% by weight, preferably 10 to 16% by weight, more preferably 12 to 14% by weight.
    • Be cured in a press, particularly between platens have a temperature of greater than 180° C. or 200° C. and/or less than 280° C. or 260° C.


Embodiments of the invention will now be described by way of example with reference to FIG. 1 which is a plan view of a mineral fibre test sample.


Shell Bone Testing:


Binders were prepared as aqueous solutions by

    • combining the ingredients of a desired binder formulation in an open, unheated reaction vessel
    • adding distilled water
    • subsequently adding a silane solution
    • agitating during addition of liquids and afterwards for several minutes to achieve complete dissolution of solids


      such that the binder solution contained approximately 45% dissolved solids as a percentage of total weight of solution. A 2-g sample of this solution, upon thermal curing at about 200° C. to 210° C. for 8 minutes, would yield 30% solids (the weight loss being attributed to dehydration during thermoset binder formation).


An evaluation of dry and “weathered” tensile strength of glass bead-containing shell bones provided an indication of the likely tensile strength and the likely durability of fibreglass insulation or other materials prepared with that particular binder. Predicted durability is based on the ratio of a shell bone's weathered tensile strength to its dry tensile strength.


To prepare the shell bones, an electric mixer was used for about two minutes to mix approximately 75 g of binder with 727.5 g of glass beads (equivalent to Quality Ballotini Impact Beads, Spec. AD, US Sieve 70-140, 106-212 micron-#7, from Potters Industries, Inc.). Any clumps from the sides of the mixer whisk and from the sides and bottom of the mixing bowl were mixed in manually using a spatula about half way through the mixing and also at the end of the mixing.


The prepared glass beads/binder mixture was added to the mould cavities of a shell bone mould (Dietert Foundry Testing Equipment; Heated Shell Curing Accessory, Model 366) which had been pre-heated to about 218° C. (425° F.). The surface of the mixture in each cavity was flattened out, while scraping off the excess mixture to give a uniform surface area to the shell bone. Any inconsistencies or gaps that existed in any of the cavities were filled in with additional glass beads/binder mixture and then flattened out. The top platen was quickly placed onto the bottom platen (to avoid producing shell bones with two differentially cured layers). The cured shell bones were removed after seven minutes, cooled to room temperature on a wire rack, labelled and placed individually in plastic storage bags. If shell bones could not be tested on the day they were prepared, the shell bone-containing plastic bags were placed in a dessiccator unit. During curing the temperature of the bottom platen ranged from about 204° C. to about 221° C. (about 400° F. to about 430° F.), while the temperature of the top platen ranged from about 227° C. to about 243° C. (about 440° F. to about 470° F.).


Procedure for Testing Breaking Strength:






    • Equipment: 5500 R Instron machine

    • Immediately prior to testing, each shell bone was removed from is plastic bag and its weight and thickness recorded.


      Weathering Procedure for Shell Bones:

    • 16 hours weathering in a pre-heated humidity chamber (65° C., 95% relative humidity)

    • upon removal shell bones were sealed in individual plastic storage bags and taken immediately for testing.


      Procedure for Measuring Gel Time:





A small amount of binder (2.0 ml) is added to the centre of a hot plate set to 150° C. and a stop watch is started. The binder is worked with a spatula until it is possible to draw the sample into a long string. The time taken from the addition of the binder to the string formation is the gel time.


Binder Formulations Tested—Inorganic Acid Precursors Compared with Citric Acid:













Test ref:
Binder formulation (by dry weight)







A
85% DMH + 15% CA + 4.8% NH4OH + 0.3% ISI0200


B
90% DMH + 10% AmSO4 + 4.8% NH4OH + 0.3% ISI0200


C
85% DMH + 15% AmSO4 + 4.8% NH4OH + 0.3% ISI0200


D
80% DMH + 20% AmSO4 + 4.8% NH4OH + 0.3% ISI0200


E
90% DMH + 10% AmPO4 + 4.8% NH4OH + 0.3% ISI0200


F
85% DMH + 15% AmPO4 + 4.8% NH4OH + 0.3% ISI0200


G
80% DMH + 20% AmPO4 + 4.8% NH4OH + 0.3% ISI0200










Binder Formulations Tested—Combined Inorganic Acid Precursor and Citric Acid Compared with Citric Acid Alone and Inorganic Acid Precursor Alone:













Test ref:
Binder formulation (by dry weight)







H
85% DMH + 15% CA + 4.8% NH4OH + 0.3% ISI0200


I
85% DMH + 10% CA + 5% AmSO4 + 4.8% NH4OH + 0.3%



ISI0200


J
85% DMH + 5% CA + 10% AmSO4 + 4.8% NH4OH + 0.3%



ISI0200


K
85% DMH + 15% AmSO4 + 4.8% NH4OH + 0.3% ISI0200





Key:


DMH = Dextrose monohydrate


CA = citric acid


NH4OH = ammonium hydroxide


ISIO200 = silane


AmSO4 = ammonium sulphate


AmPO4 = ammonium phosphate







Test Results—Inorganic Acid Precursors Compared with Citric Acid:


















Dry
Weathered
Loss in breaking
Gel time of
pH of binder



breaking
breaking
strength from
binder
solution just before


Test ref
strength (MN/m2)
strength (MN/m2)
weathering/%
solution (s)
mixing with beads




















A
1.455
1.567
−7.70
343
9.54


B
1.271
0.895
29.57
280
10.28


C
1.550
0.856
44.79
362
10.24


D
1.877
1.156
38.39
327
10.13


E
1.499
1.069
28.68
356
10.18


F
1.281
0.848
33.82
334
9.99


G
1.123
0.801
28.74
287
9.73










Test Results—Combined Inorganic Acid Precursor and Citric Acid Compared with Citric Acid Alone and Inorganic Acid Precursor Alone:


















Dry
Weathered
Loss in breaking
Gel time of
pH of binder



breaking
breaking
strength from
binder
solution just before


Test ref
strength (MN/m2)
strength (MN/m2)
weathering/%
solution (s)
mixing with beads







H
1.69
1.50
11.32
363
9.39


I
1.50
1.18
21.37
341
9.71


J
1.21
1.05
13.19
375
9.99


K
1.47
1.02
30.33
376
9.97









Results from tests carried out together (test A to G were carried out in one session and tests H to K carried out during another session) provide a useful indication of results relative to other results obtained during the same test session. It may not be reliable to compare tests results from different test sessions.


First Comparative Testing on Insulation Product:


Comparative testing of binder systems on a mineral fibre insulation product gave the following results:
















Binder tested
Description
Formulation





PF1
Comparative example -
Resin, Urea, Lignin,



standard phenol formaldehyde
Ammonia, Silane



binder


AC1
Comparative example -
Dextrose 85% Citric Acid



ammonium citrate based
15% Ammonia 4.8% Silane



binder
0.3%


Ex1
Example 1 of the present
Dextrose 85% Ammonium



invention
Sulphate 15% Ammonia




4.8% Silane 0.3%











Product
glass wool fibre insulation product, nominal density


used for
16 kg/m3, nominal thickness 75 mm, nominal width 455 mm


test:










Binder Content of Test Product LOI (Loss on Ignition) % Weight:

















Mean



Binder
LOI









PF1
6.22%



AC1
6.91%



Ex1
6.78%











Drape Test (Mean Average in mm Measured after the Periods Specified):





















Week
Week
Week



Binder
Day 1
1
3
6









PF1
55
68
60
71



AC1
83
99
80
72



Ex1
66
76
66
75











Thickness (Mean Average in mm Measured after the Periods Specified in Accordance with British Standard BS EN 823:1995)





















Week
Week
Week



Binder
Day 1
1
3
6






















PF1
76.4
75.1
75.1
75.2



AC1
75.3
73.6
72.5
74



Ex1
76
76.7
74.9
74.3











Density (Mean Average in kg/m3 Measured after the Periods Specified)





















Week
Week
Week



Binder
Day 1
1
3
6






















PF1
16.44
16.7
16.35
16.44



AC1
16.68
16.41
16.33
16.48



Ex1
16.5
16.9
16.5
16.5











Quantity of Sulphates Present mg/kg


















Sample
Sample



Binder
1
2




















AC1
240
240



Ex1
2000
2200











Parting Strength (g/g)


















Binder
Ordinary
Weathered
% loss





















PF1
248
107
56.85



AC1
230
199
13.47



Ex1
196
189
3.57











Test Procedures:


Binder Content LOI (Loss on Ignition)


A weighed sample of wool plus binder is placed in a muffle furnace set to 550° C. After a set time the wool is removed from the furnace, placed in a desiccator to cool and re-weighed. The weight loss is expressed as a percentage of the original sample weight and is known as the binder content or Loss On Ignition (LOI).


Drape Test


A single batt (or slab) is placed across two poles (each 500 mm long, 20 mm diameter) set into a wall 1 metre apart. The degree of sag in the centre of the bat is recorded. This is repeated for all of the batts in a pack and for several packs. Packs are measured at set points over a period of time to determine the long term effects of compression on the batts.


Density: measured for the samples subjected to the drape test


Quantity of sulphates present: leaching test for granular wastes in water with eluate analysis according to British standard BS EN 12457-2 at L/S10


Parting Strength


The parting strength is expressed in grams/gram being the total breaking load of six test specimens divided by their total weight.


The test is carried out on mineral fibre mats as received for testing (Ordinary Parting Strength) and after an accelerated weathering test as explained below (Weathered Parting Strength).


A first set of six samples of the form and dimensions shown in FIG. 1 are cut from the mineral fibre mat to be tested. The dimensions are:


r: radius 12.7 mm;


DC: distance between centres 44.5 mm;


a: 25.4 mm;


b: 121 mm.


The long axis of the samples should be parallel to the conveyor direction and the samples should be taken across the full width of the mineral mat. A second set of six samples is then taken in the same way.


The total weight of the first group of six samples W1 in grams is recorded.


The total weight of the second group of six samples W2 in grams is recorded; these samples are then placed in a preheated autoclave and conditioned on a wire mesh shelf away from the bottom of the chamber under wet steam at 35 kN/m2 for one hour. They are then removed, dried in an oven at 100° C. for five minutes and tested immediately for parting strength.


To test the parting strength, each sample is mounted in turn on the jaws of a 5500 Instron tensile strength machine and the maximum breaking load in grams or Newtons is recorded. If the breaking load is measured in Newtons it is converted to grams by multiplying it by 101.9. Six results in grams are obtained for each set of samples: G1 G2 G3 G4 G5 and G6 for the first set of samples and G7 G8 G9 G10 G11 and G12 for the second set of samples.


The Ordinary Parting Strength is calculated from the first set of samples using the formula Ordinary Parting Strength=(G1+G2+G3+G4+G5+G6)/W1.


The Weathered Parting Strength is calculated from the second set of samples using the formula Weathered Parting Strength=(G7+G8+G9+G10+G11+G12)/W2.


Second Comparative Testing on Insulation Product:















Product used
glass wool fibre insulation product, nominal density


for test:
7.2 kg/m3, nominal thickness 159 mm










SAMPLES: The following samples of fibreglass bats were tested:
















Target binder




content (LOI)


Example
Binder Description
for product







PF2
standard phenol formaldehyde binder of
4.5%



Resin, Urea, Ammonia, Silane


2.1
Dextrose 85% Ammonium Sulphate 15%
4.5%



Silane 0.3% (10.6% solids in binder



solution)


2.2
Dextrose 85% Ammonium Sulphate 15%
4.5%



Silane 0.3% Norjohn oil (11.4% solids in



binder solution)


2.3
Dextrose 85% Ammonium Sulphate 15%
4.5%



Silane 0.3%, 2.4% NH3 (10.6% solids in



binder solution)


2.4
Dextrose 85% Ammonium Sulphate 15%
6.0%



Silane 0.3%, 2.4% NH3 (10.6% solids in



binder solution)










Results



















PF2
2.1
2.2
2.3
2.4


























Recovery
158
mm
157
mm
163
mm
160
mm
166
mm












Recovery. % nominal
99.4%
99.0%
102.8%
100.6%
104.8%

















Parting Strength
190.8
g/g
131.7
g/g
146.7
g/g
159.9
g/g
143.9
g/g


(ASTM C-686)


Parting strength after
145.9
g/g
100.0
g/g
110.3
g/g
124.9
g/g
114.3
g/g


weathering (ASTM C-686


following conditioning


for 7 days at 90° F., 90%


relative humidity)








Claims
  • 1. A substantially formaldehyde free binder solution consisting essentially of a solution obtainable by dissolving a reducing sugar, andat least 2.5% by dry weight with respect to the reducing sugar of a material selected from the group consisting of ammonium sulphate salts, ammonium phosphate salts, ammonium nitrate salts, ammonium carbonate salts, and combinations thereofin water.
  • 2. The substantially formaldehyde free binder solution of claim 1, in which the reducing sugar consists essentially of dextrose and there is at least 7% by dry weight of the salt material with respect to dextrose.
  • 3. The substantially formaldehyde free binder solution in accordance with claim 1, in which a carboxylic acid is included or provided in the form of an ammonium salt.
  • 4. The substantially formaldehyde free binder solution in accordance with claim 1, in which the pH of the solution is greater than 7.
  • 5. The substantially formaldehyde free binder solution in accordance with claim 1, in which the binder solution has a pH which, in its conditions of use, prevents precipitation of sulphates, phosphates, nitrates or carbonates.
  • 6. The substantially formaldehyde free binder solution in accordance with claim 1, in which material selected from the group consisting of ammonium sulphate salts, ammonium phosphate salts, ammonium nitrate salts, ammonium carbonate salts, and combinations thereof makes up between 5% and 25% by dry weight of the binder solution.
  • 7. The substantially formaldehyde free binder solution in accordance with claim 1, in which the binder solution contains at least 5% solids and less than 50% solids.
  • 8. The substantially formaldehyde free binder solution in accordance with claim 1, in which the ratio by dry weight of reducing sugar to material selected from the group consisting of ammonium sulphate salts, ammonium phosphate salts, ammonium nitrate salts, ammonium carbonate salts, and combinations thereof (expressed as dry weight of reducing sugar/dry weight of ammonium salt) is in the range 2.5 to 13.
  • 9. The substantially formaldehyde free binder solution in accordance with claim 1, in which the binder solution contains between 0.1% and 1% of a silane or silicon-containing coupling agent calculated as dissolved binder solids.
  • 10. A method of manufacturing a product comprising the steps of: providing a collection of loose matter;treating the collection of loose matter with the substantially formaldehyde free binder solution of claim 1;arranging the collection of loose matter treated with the binder solution into the shape of the product; andcuring the binder by applying a source of energy.
  • 11. The method of claim 10, in which the curing of the binder is carried out by passing the arranged collection of loose matter treated with the binder solution through at least one zone of a curing oven at a temperature within the range 230° C.-300° C. with an oven residence time in the range 30 seconds to 20 minutes.
  • 12. The method of claim 10, in which the curing of the binder is carried out by between platens of a press.
  • 13. A material comprising a collection of loose matter and uncured or partially cured substantially formaldehyde free binder characterised in that the binder has a pH of greater than 6 when dissolved in water and comprises a reducing sugar, andat least 2.5% by dry weight with respect to the reducing sugar of an ammonium salt selected from the group consisting of ammonium sulphate salts, ammonium phosphate salts, ammonium nitrate salts, ammonium carbonate salts, and combinations thereof.
  • 14. The material of claim 13 in which the loose matter comprises mineral fibres.
  • 15. The material of claim 13, having more than 500 mg/kg of species selected from the group consisting of sulphates, phosphates, nitrates, carbonates, and combinations thereof.
  • 16. The material of claim 15, in which the species selected from the group consisting of sulphates, phosphates, nitrates, carbonates, and combinations thereof is derived from the ammonium salt.
  • 17. The material of claim 15, in which the binder is partially cured and comprises melanoidins.
Priority Claims (3)
Number Date Country Kind
0715100.4 Aug 2007 GB national
0807777.8 Apr 2008 GB national
0810297.2 Jun 2008 GB national
PCT Information
Filing Document Filing Date Country Kind 371c Date
PCT/EP2008/060185 8/1/2008 WO 00 3/30/2010
Publishing Document Publishing Date Country Kind
WO2009/019235 2/12/2009 WO A
US Referenced Citations (155)
Number Name Date Kind
1801052 Meigs Apr 1931 A
1801053 Meigs Apr 1931 A
1886353 Novotny et al. Nov 1932 A
2392105 Sussman Jan 1946 A
3232821 Moore et al. Feb 1966 A
3297419 Eyre Jan 1967 A
3791807 Etzel et al. Feb 1974 A
3802897 Voigt et al. Apr 1974 A
3809664 Fanta et al. May 1974 A
3826767 Hoover et al. Jul 1974 A
3856606 Fan et al. Dec 1974 A
3867119 Kasuga et al. Feb 1975 A
3911048 Vargiu et al. Oct 1975 A
4014726 Fargo Mar 1977 A
4028290 Reid Jun 1977 A
4048127 Gibbons et al. Sep 1977 A
4054713 Sakaguchi et al. Oct 1977 A
4097427 Aitken et al. Jun 1978 A
4107379 Stofko Aug 1978 A
4148765 Nelson Apr 1979 A
4183997 Stofko Jan 1980 A
4233432 Curtis, Jr. Nov 1980 A
4246367 Curtis, Jr. Jan 1981 A
4278573 Tessler Jul 1981 A
4296173 Fahey Oct 1981 A
4301310 Wagner Nov 1981 A
4322523 Wagner Mar 1982 A
4330443 Rankin May 1982 A
4357194 Stofko Nov 1982 A
4400496 Butler et al. Aug 1983 A
4464523 Neigel et al. Aug 1984 A
4524164 Viswanathan et al. Jun 1985 A
4668716 Pepe et al. May 1987 A
4692478 Viswanathan et al. Sep 1987 A
4754056 Ansel et al. Jun 1988 A
4845162 Schmitt et al. Jul 1989 A
4906237 Johansson et al. Mar 1990 A
4912147 Pfoehler et al. Mar 1990 A
4923980 Blomberg May 1990 A
5037930 Shih Aug 1991 A
5041595 Yang et al. Aug 1991 A
5095054 Lay et al. Mar 1992 A
5106615 Dikstein Apr 1992 A
5114004 Isono et al. May 1992 A
5124369 Vandichel et al. Jun 1992 A
5151465 Le-Khac Sep 1992 A
5308896 Hansen et al. May 1994 A
5318990 Strauss Jun 1994 A
5336753 Jung et al. Aug 1994 A
5336755 Pape Aug 1994 A
5340868 Strauss et al. Aug 1994 A
5371194 Ferretti Dec 1994 A
5387665 Misawa et al. Feb 1995 A
5393849 Srinivasan et al. Feb 1995 A
5434233 Kiely et al. Jul 1995 A
5480973 Goodlad et al. Jan 1996 A
5498662 Tanaka et al. Mar 1996 A
5536766 Seyffer et al. Jul 1996 A
5547541 Hansen et al. Aug 1996 A
5571618 Hansen et al. Nov 1996 A
5578678 Hartmann et al. Nov 1996 A
5582682 Ferretti Dec 1996 A
5583193 Aravindakshan et al. Dec 1996 A
5609727 Hansen et al. Mar 1997 A
5614570 Hansen et al. Mar 1997 A
5620940 Birbara et al. Apr 1997 A
5621026 Tanaka et al. Apr 1997 A
5633298 Arfaei et al. May 1997 A
5643978 Darwin et al. Jul 1997 A
5645756 Dubin et al. Jul 1997 A
5661213 Arkens et al. Aug 1997 A
5690715 Schiwek Nov 1997 A
5691060 Levy Nov 1997 A
5693411 Hansen et al. Dec 1997 A
5756580 Natori et al. May 1998 A
5788243 Harshaw et al. Aug 1998 A
5855987 Margel et al. Jan 1999 A
5885337 Nohr et al. Mar 1999 A
5895804 Lee et al. Apr 1999 A
5919831 Philipp Jul 1999 A
5925722 Exner et al. Jul 1999 A
5929184 Holmes-Farley et al. Jul 1999 A
5932344 Ikemoto et al. Aug 1999 A
5932665 DePorter et al. Aug 1999 A
5932689 Arkens et al. Aug 1999 A
5942123 McArdle Aug 1999 A
5977224 Cheung et al. Nov 1999 A
5977232 Arkens et al. Nov 1999 A
5981719 Woiszwillo et al. Nov 1999 A
5983586 Berdan, II et al. Nov 1999 A
5990216 Cai et al. Nov 1999 A
6072086 James et al. Jun 2000 A
6077883 Taylor et al. Jun 2000 A
6090925 Woiszwillo et al. Jul 2000 A
6114033 Ikemoto et al. Sep 2000 A
6114464 Reck et al. Sep 2000 A
6136916 Arkens et al. Oct 2000 A
6171654 Salsman et al. Jan 2001 B1
6210472 Kwan et al. Apr 2001 B1
6221973 Arkens et al. Apr 2001 B1
6310227 Sarama et al. Oct 2001 B1
6313102 Colaco et al. Nov 2001 B1
6319683 James et al. Nov 2001 B1
6331350 Taylor et al. Dec 2001 B1
6379739 Formanek et al. Apr 2002 B1
6395856 Petty et al. May 2002 B1
6440204 Rogols et al. Aug 2002 B1
6468442 Bytnar Oct 2002 B2
6468730 Fujiwara et al. Oct 2002 B2
6482875 Lorenz et al. Nov 2002 B2
6495656 Haile et al. Dec 2002 B1
6525009 Sachdev et al. Feb 2003 B2
6613378 Erhan et al. Sep 2003 B1
6638882 Helbing et al. Oct 2003 B1
6638884 Quick et al. Oct 2003 B2
6753361 Kroner et al. Jun 2004 B2
6818694 Hindi et al. Nov 2004 B2
6852247 Bytnar Feb 2005 B2
6858074 Anderson et al. Feb 2005 B2
6861495 Barsotti et al. Mar 2005 B2
6864044 Ishikawa et al. Mar 2005 B2
6955844 Tagge et al. Oct 2005 B2
7029717 Ojima et al. Apr 2006 B1
7067579 Taylor et al. Jun 2006 B2
7090745 Beckman et al. Aug 2006 B2
7141626 Rodrigues et al. Nov 2006 B2
7195792 Boston et al. Mar 2007 B2
7201778 Smith et al. Apr 2007 B2
20020032253 Lorenz et al. Mar 2002 A1
20020091185 Taylor et al. Jul 2002 A1
20020161108 Schultz et al. Oct 2002 A1
20030005857 Minami et al. Jan 2003 A1
20040019168 Soerens et al. Jan 2004 A1
20040033747 Miller et al. Feb 2004 A1
20040038017 Tutin et al. Feb 2004 A1
20040077055 Fosdick et al. Apr 2004 A1
20040122166 O'Brien-Bernini et al. Jun 2004 A1
20040152824 Dobrowolski Aug 2004 A1
20040249066 Heinzman et al. Dec 2004 A1
20040254285 Rodrigues et al. Dec 2004 A1
20050059770 Srinivasan Mar 2005 A1
20050171085 Pinto et al. Aug 2005 A1
20050196421 Hunter et al. Sep 2005 A1
20050202224 Helbing et al. Sep 2005 A1
20050215153 Cossement et al. Sep 2005 A1
20050275133 Cabell et al. Dec 2005 A1
20060099870 Garcia et al. May 2006 A1
20060111480 Hansen May 2006 A1
20060135433 Murray et al. Jun 2006 A1
20060252855 Pisanova et al. Nov 2006 A1
20070006390 Clamen et al. Jan 2007 A1
20070009582 Madsen et al. Jan 2007 A1
20070027283 Swift et al. Feb 2007 A1
20070123679 Swift et al. May 2007 A1
20080108741 Van Herwijnen et al. May 2008 A1
Foreign Referenced Citations (34)
Number Date Country
0044614 Jun 1981 EP
0 524 518 Jul 1992 EP
0547819 Dec 1992 EP
0 583 086 Jul 1993 EP
0 672 720 Mar 1995 EP
0 714 754 Jun 1996 EP
0 826 710 Aug 1997 EP
0 873 976 Apr 1998 EP
0 882 756 Dec 1998 EP
0 911 361 Apr 1999 EP
0 990 729 Apr 2000 EP
1 038 433 Sep 2000 EP
1 193 288 Sep 2001 EP
1 225 193 Jul 2002 EP
1 486 547 Jun 2004 EP
1698598 Sep 2006 EP
2 614 388 Oct 1988 FR
2 078 805 Jan 1982 GB
57-101100 Jun 1982 JP
58-11193 Jan 1983 JP
3-173680 Jul 1991 JP
7-34023 Feb 1995 JP
2002-293576 Sep 2002 JP
2004-60058 Feb 2004 JP
374400 Mar 1973 SU
9417004 Aug 1994 WO
9947765 Sep 1999 WO
0062628 Oct 2000 WO
03071879 Sep 2003 WO
2004076734 Sep 2004 WO
2006044302 Apr 2006 WO
2006136614 Dec 2006 WO
WO2007014236 Feb 2007 WO
WO2007024020 Mar 2007 WO
Related Publications (1)
Number Date Country
20100301256 A1 Dec 2010 US